A long with the Lippisch
DM-1 the Horten's Ho XIII represents the most advanced aerodynamic design
in the world in 1945, designed to test the low speed control of a sweeped wing
of 60°, which was the intended sweep of the supersonic Horten Ho X. The
glider was made at Hersfeld in 1943, using modified wings from the Ho III mounted
onto a new center section, the pilot sat in a gondola under the center section
trailing edge (this can just be seen in the photo) with entry being by removing
the tail cone. Take off was by means of a toe, the aircraft was said to handed
very well in all it's test flights which amounted to some ten hours in all.

Poor forward visibility, but adequate for the tow. Released at 2700
meters, and flew at speeds between 70 and 150 km/hr, straight ahead. Heavy
elevator! Ailerons normal when slow, but at 150, roll control is almost
nonexistent. With the stick all the way back, I get 70 km with no stall
tendencies. The rudder is still weak, but coordinated turns can be made.
A light roll oscillation of about 5 occurs with 45 bank; aileron application
will dampen these somewhat.

The approach is difficult, because the extended skid and the overhanging
center section, blocks the view of the runway, making landings in unfamiliar
areas very difficult.

The aircraft touched down fast and bounced a few times, the third
bounce resulting in a flat glide with only 50 km indicated. The ineffective
spoiler could not prevent the long float over the ground."

The Henschel Hs 126 used to
tow the Ho VIIIa

The next step was to be a powered version with a Argus As 10
piston engine, to carry on testing. With the outcome to be the Horten X, roughly
the same general dimensions as the Ho XIIIa weighing around 7,000 kg powered
by a single Heinkel He S 011 turbojet engine with a thrust of 1,500 kg, it was
calculated that a speed of around 1,400 km/h would be possible. By the time
of the end of the war the Horten HoXIIIa was destroyed by liberated Soviet prisoners,
only the main spar and a wing rib ever being found, ALL drawings, calculations
and plans were gone for the whole Ho XIII / X supersonic project.